Gasifiers are widely used to dispose of biomass such as dead animals, dead humans and materials and things that have been subjected to bacteria, viruses and other disease causing constituents. It is the principal object of a gasifier dealing with such biomass to reduce the biomass to ashes. More particularly, it is desirable to rid the biomass of any carbon and therefore the idea is to employ a process that produces white ashes as opposed to black ashes that suggest that there is remaining carbon in the ashes.
Generally, gasifiers include a primary chamber and a secondary or heat transfer chamber. A burner is utilized to heat inlet air that in turn heats the heat transfer chamber, which in turn heats the primary chamber. Many gasification processes can be divided into two phases, a gasification phase and a combustion or carbon phase. In the gasification phase, the biomass is heated in such a fashion that moisture is removed from the biomass. Once the moisture has been removed or substantially removed from the biomass, the process moves to the combustion process where the biomass actually burns and produces a flame. In both the gasification and combustion process, the biomass emits combustible gases that can be recirculated to the burner and burned or which under go exothermic reactions and produce heat. This makes many gasifier systems fuel efficient. Indeed, in some cases or in some phases of an gasification process, the gases or fumes given off by the biomass are sufficient to support the heat requirements of the process.
It is the aim of such gasification processes to heat the biomass so that the biomass is converted to harmless gases such as hydrogen and oxygen which oxidize to form water vapor and carbon dioxide and other harmless constituents.